JPS5820709B2 - Stud projection welding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a projection welding method, and in particular to a stud/gross projection welding method suitable for projection welding of materials having a shape in which it is difficult to drive projections or thickly coated materials. It is something.

The projection welding method is a method in which small protrusions are created on one or both sides of the vinegar solution material, and welding is performed by concentrating current and pressure on these parts.

The feature is that it is easy to weld together parts with different thicknesses,
It has many advantages, such as being able to weld to painted surfaces, having little variation in welding strength, and having little electrode wear.

However, this method cannot be applied to cases where it is impossible to punch out protrusions, such as on the surface of a long tube.

Furthermore, when welding to a painted surface, a high pressure is required to break the paint film, but if the protrusions cannot withstand this pressure and collapse, vinegar solution cannot be used.

In such cases, conventional methods have been used in which a small piece of metal is sandwiched between the materials to be welded and pressure is applied and electricity is applied, but this method has not produced sufficiently satisfactory results.

The causes of this are that when electricity is applied, small metal pieces with a small heat capacity overheat and melt, resulting in them scattering as spatter when pressurized, that heat balance cannot be maintained between the materials to be welded with different thicknesses, and that small metal pieces are This is because there is a risk of moving forward, and it is difficult to perform in a position other than horizontal.

The present invention is a stand projection welding method characterized in that small metal pieces are implanted in advance on the target material and used as welding protrusions, and by using the method of the present invention, the above-mentioned This method has made it possible to significantly expand the scope of application of the projection encyclopedia method, while eliminating the drawbacks of the above.

Next, the present invention will be explained in detail with reference to illustrated examples.

In FIG. 1, reference numeral 1 denotes a material to be subjected to which it is difficult to form welding protrusions, and is shown here as a long rectangular metal tube.

2 is a metal plate to be welded to 1, 3 is a small metal piece implanted in 1 in advance, 4 and 5 are electrodes for vinegar solution, and 6 is a welding transformer.Electrification is applied while applying pressure between electrodes 4 and 50. Then, first, the contact portion between the metal plate 2 and the metal piece 3 is heated and deformed, and then the entire metal piece 3 and the vicinity of the welding point between the metal plate 2 and the welded object 1 are heated.

If the application of pressure and current is continued, the small metal piece will soften and deform to the welded object 1. A nugget 7 is formed by adhering both metal plates 20 as shown in FIG. 2, which shows a cross section of the welded portion.

leading to.

Since the small metal piece 3 is pre-embedded with the IK of the object to be welded, the heat generated by energization is transferred to the object 1 to be welded. There is no risk of metal particles becoming molten.

In addition, if the thickness of the welded object 1 is significantly thicker than that of the metal plate 2, the temperature rise near the welding point of the welded object 1 will be delayed compared to that of the metal plate 2, but the small metal piece 3 will already be Since it is welded, there is no risk of a delay in temperature rise resulting in incomplete welding.

The welding of the small metal pieces 3 can be easily obtained by, for example, stand-welding a metal wire to the object 1 to be welded by resistance welding or impact welding, and then cutting it to an appropriate length.

That is, in general, in projection contact, there is an optimal protrusion shape depending on the plate thickness of the vinegar solution, and it is difficult to select the size of the nugget regardless of the plate thickness, but in the present invention, the size and shape of the metal pieces can be appropriately selected. By doing so, the size and shape of the nugget can be selected almost independently of the plate thickness.

In other words, the diameter of the nugget can be adjusted depending on the diameter or length of the metal wire, and when a long and narrow nugget is required, a strip metal plate is welded and cut to form a long and thin protrusion 8 as shown in Fig. 3.
If a particularly small nugget is required, a hollow protrusion 9 can be made by welding and cutting a thin metal tube.

FIG. 4 shows another embodiment in which a metal part 13° 13' is vertically mounted on an object 12 to be welded such as a pipe made of a metal plate 11 having a strong non-conductive coating 10 such as anti-corrosion coating. The case where the series resistance comes into contact with the posture is shown.

In such a case, even if acid liquid protrusions are provided on the metal parts 13 and 13' by projection processing, the non-conductive coating 10
is strong, so before it is destroyed and electricity is applied, the protrusion will collapse and welding will no longer be possible.

Furthermore, it is difficult to pinch small pieces of metal because the device is in an upright position.

According to the invention, the metal part 13.13' has a small metal piece 14.
Since the small metal piece 14.14' is placed in a stand frame in advance and then welded, the small metal piece 14.14' does not fall off, maintains its correct position, and breaks the non-conductive coating with sufficient pressure to contact the metal plate 11. Then, from the electrode 4 to the metal part 13
．． Small metal pieces 14. Metal plate 11. An electric path is formed through the small metal piece 14' and the metal part 13' to the electrode 5, making it possible to perform good welding.

Example l In Figure 5, 15 is the long side 50 mm s short side 25 mm
+ Width 0.9 made of 4 circumferences of square steel pipe with a plate thickness of 261 m
The frame body has a m y length of 1.8rIL, and 16 has the same size as the frame body, 0.6 mm.

It is a galvanized iron plate with a zinc coating amount of 305 g/WL2 on both sides.

To attach the galvanized iron plate to the frame 15, welding wires with a diameter of 2 mm were attached to the upper surface of the frame at intervals of 1100 tons at a welding pressure of 120 ky and a welding current of 6000 A.

After stand welding with an AC spono-I punching machine under the condition of 10 cycles of energization time, the height was 1. A small piece of metal for a welding projection (1T) is cut into strips, a galvanized iron plate 16 is placed on top of this, and a welding pressure of 180kg and a welding current of 12% are applied to each welding projection.
Projection welding was performed using a planar electrode at 00OA and 12 cycles of current application.

As a result, the tensile strength of each contact point was an average of 210 degrees per point, no dents were formed on the surface of the steel plate due to welding, and damage to the galvanized layer was slight.

When such direct welding is performed using the conventional method, it is not possible to drive a welding protrusion into the square steel pipe, so spon welding is performed using a spherical or truncated conical electrode, and the strength of the welding point is different from that of the method of the present invention. Although the same value was obtained, a depression with a diameter of 4 to 5 μm and a depth of about 0.1 μ was formed on the surface of the galvanized iron plate, and the galvanized layer was damaged, and the electrode was significantly contaminated by zinc.

Example 2 In Fig. 6, 18 is a cylinder made of a steel plate with a diameter of 20C) 0.8 myn in thickness, and 19.19' is a hanging hand made of steel plate with a thickness of 0.6 mm. It is a metal fitting.

When attaching the metal fitting to the cylinder 18, first attach the hanging metal fitting 1.
Welded iron wire with a diameter of 1.6 mm to each inner surface of 9.19' with a pressure of 110 ky and a welding current of 4000 A.

After stand welding with an AC sponto extraction machine under the condition of 10 cycles of current application, this was cut to a height of 1.0 mm to form a small metal piece 20 for the welding protrusion, and the hanging metal fitting was symmetrically attached to the outer surface of the steel plate cylinder 18. The welding force was 180 kp, the final welding force was 350 kp, and each was held down by a flat electrode.
kg, capacitor sponge under the condition of welding voltage 300V)
When series glossection vinegar solution was applied by welding, an average tensile strength of 148 kg was obtained at the welding point on the positive electrode side, and an average tensile strength of 13 Qk& was obtained at the welding point on the negative electrode side.

On the other hand, when projecting projections using the conventional method by punching out vinegar solution protrusions on a hanging metal fitting, the coating was so strong that the protrusions were crushed before the coating was destroyed, making it impossible to conduct electricity.

As described above, according to the present invention, it is difficult to form a welding protrusion, or even if it is possible to form a welding protrusion, the protrusion cannot be formed into a protrusion with the strength necessary for energization, such as a metal body or a strong non-conductive coating. Projection welding can be applied to any type of metal body covered with glaze projection, and the size and shape of the nugget can be selected almost independently of the thickness of the workpiece. The scope of application can be significantly expanded.

[Brief Description of the Drawings] Figs. 1 and 4 are schematic diagrams showing embodiments of the present invention, Fig. 2 is a sectional view of a welded part, and Fig. 3 is a schematic diagram showing other embodiments of the protrusion shape; FIGS. 5 and 6 are perspective views showing other embodiments. 1.12,15,18...Fusing object, 2,13
13', 16, 19, 19'... Metal plate or metal fitting to be welded to the welded object, 3, 8, 9, 14゜1
4', 17, 20...Small metal pieces for the protrusion,
4゜5... Electrode for welding, 6... Transformer for vinegar solution, 10... Non-conductive coating, 11...
...Metal plate.

Claims (1)

[Claims] 1. A stand projection welding method characterized by placing small metal pieces on the material to be welded in advance and using them as welding protrusions.